The invention relates to a process for operating a plant for the cracking of hydrocarbons, whereby the hydrocarbons are indirectly heated in the cracking furnace by heat incurred in the combustion of a heating medium with oxygen containing gas. More specifically, the invention relates to a process where hydrocarbons are cracked to form olefin-gases, such as ethylene (C.sub.2 H.sub.4).
It is known in processes for the generation of high-olefinic cracked gases to feed stock, such as naphtha, ethane, to cracking furnaces, whereupon cracked gases leaving the furnaces are cooled and fed to compressors. After compression, the cracked gases are further processed to obtain, for example, ethylene.